NASA Sunrise Mission Reveals Sun's Atmosphere in New Images

NASA scientists are learning a little bit more about the sun's atmosphere. Three months after the flight of the solar observatory SUNRISE, researchers have gathered new information about a layer on the sun called the chromosphere, learning a bit more about our nearest star.

The chromosphere is a layer of the sun's atmosphere that lies between the sun's visible surface and the corona, which is the sun's outer atmosphere. This thin, corrugated layer is constantly in motion with different temperatures of hot material mixing over a range of heights, stretching from the sun's surface to many thousands of miles up. The temperatures continue to rise further into the corona and no one knows exactly what powers any of that heating.

"In order to solve this riddle it is necessary to take as close a look as possible at the chromosphere--in all accessible wavelengths," said Sami Solanki, the principle investigator for Sunrise, in a news release.

Sunrise is the largest solar telescope to fly above the atmosphere. Weighing in at almost 7,000 pounds, it soared 20 miles into the air and floated five days over the Atlantic. During its journey, it gathered as much information as possible about the chromosphere. The results were the highest-resolution images to date in ultraviolet light of this thin layer of the sun.

What did these images tell researchers about the sun? They painted a complex picture of the chromosphere. Where the sun is quiet and inactive, dark regions with a diameter of about 600 miles can be seen surrounded by bright rims. This pattern is created by the enormous flows of solar material rising up from within the sun, cooling off and then sinking down again. Bright points also flash up occasionally;  these bright points in particular could be signs of magnetic flux tubes, which are the building blocks of the sun's magnetic field.

"These first analyses are extremely promising," said Solanki. "They show that the ultraviolet radiation from the chromosphere is highly suitable for visualizing detailed structures and processes."

Currently, the researchers are still examining the images as they look forward to their next mission.